PROJECT SUMMARY/ABSTRACT Each year in the US, 6000+ healthy individuals donate a kidney to a loved one, friend or stranger amounting to 142,111 individuals who have donated since 1988. For these healthy individuals, live donor nephrectomy is associated with a 25-40% decline in renal function, which increases their risk for chronic kidney disease (CKD) and end-stage renal disease (ESRD). However, recent evidence suggests that Black living kidney donors are at an even higher risk of these long-term morbidities than White donors. The 15-year postdonation risk of ESRD for Black donors is 154 per 10,000 compared to 49 per 10,000 for White donors. While compelling evidence points to genetic risk factors as key components of this difference, a substantial knowledge gap exists regarding the contribution of socioeconomic status (SES) and local environment of donors. Routine postdonation follow-up and care management could potentially identify early events on the pathway to CKD and ESRD ? including diabetes (DM), hypertension (HTN) and glomerulonephritis (GN) as these conditions are easily detected with routine vital signs, and blood and urine tests. Our group recently reported that only 50% of transplant hospitals achieve the mandated, routine follow-up for their donors. Further, follow- up attrition is associated with donors that are young, black, male, uninsured, and with fewer years of education. It is possible that socioeconomic and local environment disadvantage may potentiate follow-up attrition and increase rate of progression to CKD/ESRD in an already genetically at risk population. To better understand the impact of SES and environment on post-donation CKD/ESRD, we will leverage a major, ongoing, R01-funded, multicenter study that uses survey data linked to administrative databases to address the following aims: (1) To characterize the SES and local environment resources of Black vs. White living kidney donors; (2) To quantify the postdonation risk of CKD/ESRD attributable to low SES and disadvantaged environments; and (3) To examine health behavior of Black vs. White donors according to SES and environment. These aims are highly feasible given the rich primary data collection of parent study. We hypothesize that Black and White donors with low SES and from disadvantaged environments will have a higher incidence of postdonation DM, HTN, GN and CKD/ESRD. If the proposed aims are achieved, we will have a better understanding of which variables modify the relationship between race and outcomes and at what threshold of social disadvantage a difference is observed. It could also change clinical practice by 1) informing personalized follow-up care plans based on donor social circumstances, and (2) preventing exclusion of disadvantaged populations from national-based monitoring interventions.